Weyl-Underhill-Emmrich quantization and the Stratonovich-Weyl quantizer

Weyl-Underhill-Emmrich (WUE) quantization and its generalization are considered. It is shown that an axiomatic definition of the Stratonovich-Weyl (SW) quantizer leads to severe difficulties. Quantization on the cylinder within the WUE formalism is discussed.Comment: 15+1 pages, no figure

Absolute energy curves from late B-type supergiants

Energy curves were determined for six late B and early A type supergiants using IUE data and other ultraviolet and ground based photometry. Effective temperatures and angular diameters are presented as well as estimates of the outflow velocity of the wind. All six stars show a strong Balmer continuum in emission; the Ia supergiants also show an infrared excess which reaches into the visible range. Evidence is found for the presence of a warm mantle as well as for wind from the Ia stars

The savannah hypothesis of shopping

The official published of the article can be found at the link below

The structural and diagenetic evolution of injected sandstones: examples from the Kimmeridgian of NE Scotland

Abstract: Injected sandstones occurring in the Kimmeridgian of NE Scotland along the bounding Great Glen and Helmsdale faults formed when basinal fluids moved upward along the fault zones, fluidizing Oxfordian sands encountered at shallow depth and injecting them into overlying Kimmeridgian strata. The orientation of dykes, in addition to coeval faults and fractures, was controlled by a stress state related to dextral strike-slip along the bounding fault zones. Diagenetic studies of cements allow the reconstruction of the fluid flow history. The origin of deformation bands in sandstone dykes and sills was related to the contraction of the host-rocks against dyke and sill walls following the initial stage of fluidized flow, and these deformation bands are the earliest diagenetic imprint. Early non-ferroan calcite precipitated in injection structures at temperatures between 70 and 100 8C, indicating that it precipitated from relatively hot basinal fluids that drove injection. Coeval calcite-filled fractures show similar temperatures, suggesting that relatively hot fluids were responsible for calcite precipitation in any permeable pathway created by dextral simple shear along the faults. During progressive burial, percolating sea water was responsible for completely cementing the still relatively porous injected sandstones with a second generation of ferroan calcite, which contains fluid inclusions with homogenization temperatures below 50 8C. During this phase, depositional host sandstones were also cemented

Effect of Maple Sugaring on Leaf Litter Decomposition in Vermont Forests

The purpose of this study was to examine if tapping sugar maple trees alters the decomposition of their leaf litter. To do this, leaf litter collection baskets were placed in tapped and untapped stands of maple trees in Proctor Maple Research Center in Underhill, Vermont. Litter was allowed to collect in the baskets throughout the fall 2016 season, and then the leaves were dried, weighed, and run through a nutrient analyzer. The nutrient analysis yielded percent nitrogen by weight, percent carbon by weight, and carbon nitrogen ratios for each sample. It was found that the leaf litter of untapped samples had significantly more nitrogen and significantly lower carbon nitrogen ratios than the leaf litter collected in the tapped stand. This indicates a likely change in the decomposition of the leaves in each stand, because nutrient ratios have been shown to alter decomposition rates for leaves. One of the implications of slowed decomposition is retarded nutrient cycling, which could lead to a reduction in available nitrogen, a limiting nutrient for sugar maples, in the forest’s soil. More research should be done to determine the origin of the difference in nutrients. Additionally, a longer-term study is necessary to monitor the decomposition rates in this forest

Is government ownership of banks really harmful to growth?

We show that previous results suggesting that government ownership of banks has a negative effect on economic growth are not robust to adding more 'fundamental' determinants of economic growth, such as institutions. We also present regression results from a more recent period (1995-2007) which suggest that, if anything, government ownership of banks has been associated with higher long run growth rates, even after controlling for institutions and other variables suggested by the growth literature. Drawing on the current global financial crisis, we provide a conceptual framework which explains why under certain circumstances government owned banks could have a greater effect on economic growth than privately-owned banks

A new model for the structure of the DACs and SACs regions in the Oe and Be stellar atmospheres

In this paper we present a new mathematical model for the density regions where a specific spectral line and its SACs/DACs are created in the Oe and Be stellar atmospheres. In the calculations of final spectral line function we consider that the main reasons of the line broadening are the rotation of the density regions creating the spectral line and its DACs/SACs, as well as the random motions of the ions. This line function is able to reproduce the spectral feature and it enables us to calculate some important physical parameters, such as the rotational, the radial and the random velocities, the Full Width at Half Maximum, the Gaussian deviation, the optical depth, the column density and the absorbed or emitted energy. Additionally, we can calculate the percentage of the contribution of the rotational velocity and the ions' random motions of the DACs/SACs regions to the line broadening. Finally, we present two tests and three short applications of the proposed model.Comment: 9 pages, 5 figures, accepted for publication in PAS

A Spectroscopic Study of Field and Runaway OB Stars

Identifying binaries among runaway O- and B-type stars offers valuable insight into the evolution of open clusters and close binary stars. Here we present a spectroscopic investigation of 12 known or suspected binaries among field and runaway OB stars. We find new orbital solutions for five single-lined spectroscopic binaries (HD 1976, HD 14633, HD 15137, HD 37737, and HD 52533), and we classify two stars thought to be binaries (HD 30614 and HD 188001) as single stars. In addition, we reinvestigate their runaway status using our new radial velocity data with the UCAC2 proper motion catalogs. Seven stars in our study appear to have been ejected from their birthplaces, and at least three of these runaways are spectroscopic binaries and are of great interest for future study.Comment: 21 pages, 1 figure, 7 tables; Accepted to Ap